Ground anchor

ABSTRACT

A three- or four-point support type ground anchor is provided which may be easily driven into and positively set in the ground and may provide the maximum effective earth bearing surface area. The ground anchor comprises an inverted U-shaped resisting or earth bearing plate whose leg portions or resisting members may be bent outwardly in the opposite directions from each other successively along several horizontal lines. Until the ground anchor is driven to a predetermined depth, the bending of the resisting plate, that is the resisting members are prevented by a pair of driving-control rods so that they may be straightly driven into the ground. After the ground anchor has been driven to a predetermined depth, the driving control rods are released so that the resisting members may come off the control rods and follow the curved paths in the opposite directions. The load from the structure through a guy strand may be positively supported by the resisting plate, a pair of lift plates, and a pair of lift rods joined to the lower ends of the resisting members and an auxiliary rod or rods joined to the upper end of the resisting plate.

Waite Watanabe aent H 1 Jan. 15, 11974 GROUND ANCHOR [22] Filed: Apr. 7,1972 [2]] Appl. No.: 242,036

Related US. Application Data [63] Continuation-impart of Ser. No.86,814, Nov. 4,

1970, Pat. NO. 3,662,505.

[30] Foreign Application Priority Data May 10, 1971 Japan 46/30425 [52]US. Cl. 52/162, 52/164 [51] lint. Cl E02d 5/80 [58] Field of Search52/155, 158, 160, 52/162, 163, 164,165

[56] References Cited UNITED STATES PATENTS 3,662,505 5/1972 Watanabe eta1 52/164 X 853,331 5/1907 Alyea r 52/164 2,029,740 2/1936 Rosner 52/1623,276,173 10/1966 Bowman et al. 52/164 3,601,941 8/1971 Watanabe et a152/162 X 7 Primary Examiner-Frank L. Abbott Assistant Examiner-John R.Masterman Att0rneySaul Jecies [57] ABSTRACT A threeor four-point supporttype ground anchor is provided which may be easily driven into andpositively set in the ground and may provide the maximum effective earthbearing surface area. The ground anchor comprises an inverted U-shapedresisting or earth bearing plate whose leg portions or resisting membersmay be bent outwardly in the opposite directions from each othersuccessively along several horizontal lines. Until the ground anchor isdriven to a predetermined depth, the bending of the resisting plate,that is the resisting members are prevented by a pair ofdrivingcontrolrods so that they may be straightly driven into theground. After the ground anchor has been driven to a predetermineddepth, the driving control rods are released so that the resistingmembers may come off the control rods and follow the curved paths in theopposite directions. The load from the structure through a guy strandmay be positively supported by the resisting plate, a pair of liftplates, and a pair of lift rods joined to the lower ends of theresisting members and an auxiliary rod or rods joined to the upper endof the resisting plate.

4 Claims, 12 Drawing Figures PATENYEDJM 15 1914 I sum it? 7 L51 7 J IE.5.

GROUND ANCHOR This is a continuation-in-part of my prior patentapplication, Ser. No. 86,814, filed on Nov. 4, 1970, now U.S. Pat. No.3,662,505.

BACKGROUND OF THE INVENTION The present invention relates to astationary ground anchor to be driven into and set in the ground forguying a wood pole or steel tower for power transmission or an antennastructure.

The conventional ground anchors which have been widely used are ofone-point support type generally comprising a relatively small steelresisting plate, which is driven into the ground, and a guy wireconnection rod attached to the center of the upper surface of theresisting plate. In order to support a greater load or structure, theimproved ground anchors of two-point support type have come to be usedin which a guy connection rod is attached to the lower end of aresisting plate whereas an auxiliary rod to the upper or base end of theresisting plate so that the latter may hold a load at two points.Therefore the resisting plate may develop excellent holding power bybearing against undisturbed earth in a stable manner. However, eventhese twopoint support type ground anchors are unable to developsufficiently high holding power for guying large structures which haverecently become greater and greater. Furthermore when a resisting platehaving a large earth bearing surface area is used, it becomes extremelydifficult to drive it into the ground in one direction over a longdistance to a predetermined depth cutting through the earth against theincreasing soil resistance.

In order to overcome this problem, there has been proposed a groundanchor of the type in which two separate resisting plates are driveninto the ground in such a manner that they may be integrally joinedtogether in the ground. However, the ground anchors generally developholding power by bearing against undisturbed earth by the resistingplate in the direction in which the uplift is applied to the groundanchor, so that the latter must be driven into the ground with the leastsoil resistance to a predetermined depth and then must be so positionedas to bear against undisturbed soil in the direction in which thelifting force is applied. In this respect, the conventional groundanchors of the aforementioned type have the defect that they are not setin the ground as desired because the ground anchor which is being driveninto the ground cannot be seen from the ground surface and cannot becontrolled in position. This defect is very serious especially when theground anchor is driven by the conventional method into and set inground in which the soil has been compacted very hard.

SUMMARY OF THE INVENTION It is therefore the primary object of thepresent invention to provide an improved ground anchor which mayovercome the problems and defects encountered in the conventional groundanchors.

Briefly stated, the present invention is characterized in that aninverted U-shaped resisting or earth bearing plate is made by bending asteel plate having a ridge portion which is outwardly bulged along thelongitudinal center line of the steel plate, each of two leg portions(which will be referred in this specification as resisting members)having a series of reinforcing members which are formed by dividing theridge portion by grooves, when driven into the ground the leg portionsor resisting members being bent outwardly away from each othersuccessively along the grooves between the reinforcing members under theblows given to the ground anchor in combination with the soil resistanceso that the resisting members may be set in the ground with desiredcurvature.

The present invention is further characterized in that a driving-controlrod is inserted into each of the series of reinforcing members of theresisting members so that they may be prevented from being bent and maybe driven straight to a desired depth, and when the ground anchor hasreached the desired depth the control rods may be released and left inthe ground upwardly relative to the resisting members due to the inertiaof the driving-control rods when the ground anchor is further driveninto the ground to permit the resisting members to come off thedriving-control rods and to follow the curved paths in oppositedirections, whereby the resisting members may be set in correct positionin the ground to provide sufficient soil bearing surface areas.

The present invention is further characterized in that the lower ends oflift plates, which in turn are joined to lift rods, are attached to thelower or leading ends of the resisting members and the lower end or endsof auxiliary rod or rods are attached to the upper end of the resistingplate whereas the upper ends of these lift rods and auxiliary rod orrods are coupled to a guy wire connection rod so that the ground anchormay support a load at three or four points.

The ground anchor in accordance with the present invention is simple inconstruction, and may be easily driven into and set in ground so thatthe excellent holding power may be developed.

The above and other objects, features and advantages of the presentinvention will become more apparent from the following description ofthe preferred embodiments thereof taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of a firstembodiment of a ground anchor in accordance with the present invention;

FIGS. 2 and 3 are side and perspective views thereof;

FIG. 4 is a front view of a driving pipe with driving control rods usedfor driving the ground anchor of the present invention shown in FIGS. 13;

FIG. 5 is a top view thereof;

FIG. 6 is a front view of a driving rod used in conjunction with thedriving pipe shown in FIG. 4;

FIGS. 7 11 are views used for explanation of the method and process ofdriving the ground anchor of the present invention; and

FIG. 12 is side view of a second embodiment of the present inventionwhich is shown as being set in the ground.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the accompanyingdrawings and particularly to FIGS. 1, 2 and 3, the first embodiment of aground anchor in accordance with the present invention will be nowdescribed in detail. A ground anchor generally designated by 20comprises a resisting plate 21, the most important part of the groundanchor, which is made of a rectangular plate whose four corners are cutoff at an appropriate angle as best shown in FIG. 1 and which is formedwith a ridge extending along the longitudinal axis of the plate. Therectangular plate is bent symmetrically back upon itself along thehorizontal center line into the inverted-U-shape best shown in FIG. 3.Thus the resisting plate 21 comprises two resisting members 21a and 21band a plurality of reinforcing members 24a1 24a6 and 24bl and 24b6 (inthe instant embodiment each resisting member being shown as having sixreinforcing members) which are formed by cutting the longitudinal ridgeat 23a] 23a5 and 23b1 and 23b5 so that the reinforcing elements 240124a6 and 24b1 24b6 may be spaced apart from each other by an appropriatedistance. As best shown in FIG. 3, a portion of the ridge at the top ofthe resisting plate 21 is cut off to provide an opening 22. It is seenthat the longitudinal ridge may be formed by an appropriate metalforming method.

To the lower ends of the resisting members 21a and 21b of the resistingplate 21 are securely fixed, for example by welding, control or guideplates 25a and 25b which have sharp edges and extend downwardly beyondthe leading lower edges of the resisting members 21a and 21b. Thesecontrol or guide plates 25a and 25b serve to cut through the earth andguide the resisting plate 21 when it is driven into the ground. Whenforces in excess of a predetermined magnitude are exerted upon theresisting members 21a and 21b so as to move them away from each otheroutwardly, they are bent outwardly along the grooves 23a1 23:15 and 23b123b5 between the reinforcing elements 24111 24aand 24b1 24b6 until theadjacent reinforcing members abut against each other as will bedescribed in more detail hereinafter. Thus, when the space between thereinforcing members 24al 24a6 and 24b1 24b6 is appropriately determined,a desired curvature of the bent resisting members 210 and 21b will beobtained. According to the present invention, and in order to facilitatethe bending of the resisting members 21a and 21b, elongated grooves 26a126a5 and 26b1 26b5 having an appropriate length are formed in theresisting members 21a and 21b in line with the grooves 23al 23:15 and23b1 23b5 on both sides of the ridge or reinforcing members. It is seenthat in place of the elongated grooves, recesses may be formed.

The lower ends of the lowermost reinforcing members 24:11 and 24bl areclosed by sealing and impactreceiving end members 27a and 27b,respectively, which are fixed to the reinforcing members by welding orthe like so that the ground soil may be prevented from entering into thelowermost reinforcing members 2401 and 24bl and the blows for drivingthe ground anchor into the ground may be transmitted to the resistingmembers 21a and 21b as will be described in more detail hereinafter.

Impact-receiving members 280 and 28b are firmly attached at right anglesrelative to the control or guide members 25a and 25b, for example bywelding, to the control or guide members 25a and 25b and to thelowermost reinforcing members 24a and 24b1 along the longitudinal axesthereof. As best shown in FIG. 2, the pointed edges of theimpact-receiving members 28a and 28b extend downwardly beyond those ofthe control members 250 and 25b. These impact-receiving members 28a and28b serve to cut through the soil when the anchor is driven into theground so that the driving of the resisting members 21a and 21b may befacilitated.

Auxiliary members 30a and 30b are securely attached to the lowerportions of lift plates 29a and 29b respectively in such a manner as toform a space therebetween. The lower ends of lift plates 29a and 29b arepivoted with pivot pins 310 and 31b, respectively, to theimpact-receiving members 280 and 28b which are inserted between the liftplates 29a and 29b and the auxiliary members 30a and 30b.

A pincetteor pincers-like lift rod 33 comprises two leg members 33a and33b and a ring or eye portion 32, and the lower ends of the leg members33a and 33b are split axially and fitted over the upper edges of thelift plates 29a and 29b so that they may be firmly fixed thereto, forexample by welding. A guy-wire-retaining rod 36 has two eyes 34 and 35of which the lower eye 34 is loosely coupled with the eye 32 of the liftrod 33, as best shown in FIG. 1.

The lower end of an auxiliary rod 37a which is used to transmit thebearing force of the resisting plate 21, is fitted into a bulged portion38a of the uppermost reinforcing member 24a6 and securely fixed thereto,for example welding. The auxiliary rod 37a extends through a couplingring 39 firmly fixed to the lift rod 33 immediately below the eye 32,and the upper end of the auxiliary rod 37a is bent over so that it mayengage with the coupling eye 39 as will be described in more detailhereinafter. The length of the auxiliary rod 37a extending upwardlybeyond the coupling eye 39 is made equal to the distance between thepivot pin 31a of the lift rod 29a and the bulged portion 38a of thereinforcing member 24a6 for a reason to be described in more detailhereinafter.

Next referring to FIGS. 4, 5, and 6, a driving tool for driving theground anchor described above into the ground, will be described. Thedriving tool generally comprises a driving pipe 50, two driving-controlrods 55a and 55b extending downwardly from the lower end of the drivingpipe 50, and a driving rod 60. The lower end of the driving pipe 50 isclosed with an end member 52 which is firmly attached thereto by weldingor the like and is provided with an elliptical hole 53 which is smallerthan the cross section of the driving pipe 50. Along the minor diameterof this elliptical hole 53 is fixed a partition 54 so as to divide thehole 53 further into two smaller holes. The driving-control rods 55a and55b whose diameter is smaller than that of the divided parallel holesextend in parallel to each other through these divided smaller holes toa predetermined length.

As best shown in FIG. 6, the driving rod generally indicated bycomprises a rod member 61 which is longer than the driving pipe 50 and ahammer head 62 fixed to the lower end of the rod member 61. When thedriving rod 60 is inserted into the driving pipe 50, and then raised anddropped, the driving impact is transmitted to the head 56 of thedriving-control rods 55a and 55b.

Next the mode of driving the ground anchor will be describedhereinafter. The driving control rods 55a and 55b are inserted into thereinforcing members 2401 24a6 and 24b1 24b6 of the resisting members 210and 21b respectively until the lower ends of the control rods 55a and55b abut the impact receiving end members 27a and 27b. The ground anchor20 is vertically placed in a hole dug in the ground, with theimpact-receiving members 280 and 28b directed downwardly as best shownin FIG. 7. The driving rod 60 is inserted into the driving pipe 50, andrepeatedly raised and dropped so that the driving impact may betransmitted to the head 56 of the driving-control rods 55a and 55b andhence to the resisting members 21a and 21b through the impact-receivingends 28a and 28b. As a consequence the ground anchor 20 is graduallydriven into the ground. In this case, since the driving-control rods 55aand 55b are inserted into the reinforcing members 2401 24a6 and 24bl24b6, the resisting members 21a and 21b are prevented from bendingoutwardly when the ground anchor is driven to a predetermined depth.

When the ground anchor 20 is set to a predetermined depth, the groundanchor driving operation is temporarily suspended so that the drivingrod 60 may be pulled away from the driving pipe 50. Thereafter theground anchor driving operation is resumed by directly giving heavyblows to the driving pipe with a large hammer or the like as shown inFIG. 8, so that the driving impacts are directly imparted to the upperedge of the resisting plate 21 and not to the lower end of the resistingplate 21. When the driving impacts are driven by the driving rod 60, theimpacts are transmitted to the lower edges of the resisting members 21aand 21b through the control rods 55a and 55b and the impact receivingends 27a and 27b. Since the driving impacts are not imparted to thedriving-control rods 55a and 55b which are inserted into the reinforcingmembers 24al 24a6 and 24b1 24b6 of the resisting members 21a and 21b,these rods are left behind the resisting members 21a and 21b when thelatter are driven into the ground under the blows directly given fromthe driving pipe 50. As a result the lowermost reinforcing members 24411and 24b1 and hence the control or guide members 25a and 25b attachedthereto are released from the driving-control rods 55a and 55b. That is,the resisting members 21a and 21b are gradually released from thecontrol of the driving-control rods 55a and 55b which have so far servedto drive the resisting members 21a and 21b straight into the ground.Thus, under the driving impacts imparted to the upper edge of theresisting plate 21 and under the influence of the soil pressuresimparted to the lift plates 29a and 29b, the lift rod 33 and the endmembers 27a and 27b at the ends of the lowermost reinforcing members24a1 and 24b1, the resisting members 21a and 21b are gradually benttoward the lift plates 29a and 29b, respectively, as shown in FIG. 9.That is, the resisting members 21a and 21b are bent along the grooves23a1 and 23bl between the reinforcing members 24al and 24a2 and betweenthe reinforcing members 24bl and 24b2 toward the lift plates 29a and29b, respectively. Thus the resisting members 21a and 21b start to bedriven along curved paths in the ground.

However, when bending of the resisting members 21a and 21b is permittedwithout limitation, the curvature of the driving paths is increased tosuch an extent that the driving of the resisting members 21a and 21balong the curved paths becomes impossible. Therefore the spacing betweenthe reinforcing members 2401 and 24:12 and 24bl and 24b2 is sodetermined that the driving along the curved path of the resistingmembers 21a and 22b may be possible. That is, the curvature of thecurved driving path is limited.

When the driving blows are successively applied to the driving pipe 50,the resisting plate members 21a and 21b are successively bent along thegrooves be tween the reinforcing members 24al and 24a2; 24b] and 24b2;24a2 and 24a3; 24b2 and 24b3; 24a3 and 24a4; 24123 and MM; and so on,and are driven into the ground following along the curved pathsinitially made by the control or guide members 25a and 25b. Therefore asshown in FIG. 10, the resisting members 21a and 21b are greatly movedaway from each other and driven into the ground along respective curvedpaths, so that they may be set in the ground. Thereafter the drivingpipe 50 is pulled out together with the driving-control rods a and 55b.Thus the driving of the ground anchor is completed.

When the ground anchor 20 is driven into the ground, the auxiliary rod37a is pulled by the resisting member 21a and the top end 40a of theauxiliary rod 37a is engaged with the hook 40a when the ground anchor isfinally set into the ground. Therefore the uplifting force exerting tothe guy-wire retaining rod 36 is sustained by three parts, that is thetwo leg members 33a and 33b of the lift rod 33 and the auxiliary rod 37aso that the resisting plate 21 may support the load at three points,that is the right and left ends and the upper end. Thus, the desiredstrong and stable holding force may be produced.

When the resisting members 210 and 21b are driven into the ground alongthe curved paths in the manner described above, the lift plates 29a and29b and the lift rod 33 are forced to displace themselves slantinglyunder the soil pressure. Therefore, when the soil is soft there arisesno problem, but when the soil is hard, the leg members 33a and 33b ofthe lift rod 33 are bent as shown in FIG. 10. However, when the upliftload is 'once applied to the guy-wire-retaining rod 36, these legmembers 33a and 33b are extended straight as shown in FIG. 11.

When the mechanical strength of the ground anchor is desired to beincreased, there may be provided an additional auxiliary rod 37b similarin both construction and function to the first-mentioned auxiliary rod37a. The lower end of the auxiliary rod 37b is inserted into abulged'portion formed at the uppermost reinforcing member 24b6 and issecurely fixed thereto by welding or the like, whereas the upper endportion is bent over as shown at 40b so that it may engage with the eye39 when the auxiliary rod 37b is driven into the ground as in the caseof the auxiliary rod 37a. Therefore, when the ground anchor is driveninto the ground, the resisting plate 21 may in this case support theload at four points, that is at the right and left ends of the right andleft resisting members, and also at the upper ends thereof. In otherwords, the resisting plate 21 is connected at these four points to thelift rod 33 through the lift plates 29a and 29b and to the auxiliaryrods 37a and 37b, so that the sufficiently strong bearing force may beproduced.

Only the essential features of the present invention has been described,and it will be understood that various modifications and variations canbe effected without departing from the true spirit of the presentinvention.

What is claimed is:

l. A ground anchor, comprising a resisting plate of inverted U-shape;

a pair of lift rods having lower ends hinged to the lower ends of saidresisting plate;

a guy-wire-retaining rod having a lower end coupled to respective upperends of said pair of lift rods which are joined to each other; and

an auxiliary rod having a lower end joined to an upper end of saidresisting plate,

said resisting plate being provided with a ridge portion which bulgesoutwardly along a longitudinal axis of said resisting plate and saidridge portion being divided into a plurality of reinforcing memberswhich are spaced apart from each other by respective grooves so thatsaid resisting plate may be easily bent outwardly along the groovesbetween said plurality of reinforcing members,

said auxiliary rod being loosely fitted into a coupling annulus formedat said upper ends of said pair of lift rods in such a manner that anupper end of said auxiliary rod engages with said coupling annulus whensaid ground anchor has been driven into and set in the ground.

2. A ground anchor as set forth in claim 1, wherein said plurality ofreinforcing members are semi-elliptical in cross section and are spacedapart from each other by a predetermined distance so that said resistingplate may be bent with a predetermined curvature when said ground anchorhas been driven into the ground.

3. A ground anchor as set forth in claim 2, wherein the lower ends ofthe lowermost reinforcing members of said resisting plate are closedwith end members, wherein control or guide members are securely joinedto rear surfaces of the lower end portions of said resisting plate insuch a manner as to extend downwardly beyond said lowermost reinforcingmembers, and wherein driving-control rods are inserted through saidplurality of reinforcing members until they engage with said end membersso that when said ground anchor is driven into the ground said resistingplate may be maintained straight but when the driving impacts aredirectly applied to said upper end of said resisting plate saiddriving-control rods are left upwardly behind said resisting platebecause of the inertia of said driving-control rods, so that the legportions of said resisting plate are outwardly moved away from eachother and follow curved paths in opposite directions.

4. A ground anchor as set forth in claim 3, wherein said resisting platehas an additional auxiliary rod whose lower end is also firmly fitted tosaid upper end of said resisting plate and which is loosely fitted intosaid coupling annulus together with the first-mentioned auxiliary rod,the upper end of said additional auxiliary rod also engaging with saidcoupling annulus when said ground anchor has been driven and set intothe ground.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.5,785,100 Dated January 15, 197 O Inventor(s) Hikoitsu Watanable It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below: .1

On the Cover Sheet, in item add the following:

-- and Sanji Genma, 4-8, l-ohome, Ebar'a-Cho, Nakano-ku,

Tokyo, Japan Signed and Scaled this fourteenth D a y of October 1 9 75[SEAL] A ttest:

RUTH C. MASON C. MARSHALL DANN Arresting Officer (ummissiuner uj'Patentsand Trademarks 'ORM PO-1050 (10-69) USCOMM-DC 60376-P69 U.S. GOVERNMENTPRINTING OFFICE: 3 I a l

1. A ground anchor, comprising a resisting plate of inverted U-shape; apair of lift rods having lower ends hinged to the lower ends of saidresisting plate; a guy-wire-retaining rod having a lower end coupled torespective upper ends of said pair of lift rods which are joined to eachother; and an auxiliary rod having a lower end joined to an upper end ofsaid resisting plate, said resisting plate being provided with a ridgeportion which bulges outwardly along a longitudinal axis of saidresisting plate and said ridge portion being divided into a plurality ofreinforcing members which are spaced apart from each other by respectivegrooves so that said resisting plate may be easily bent outwardly aLongthe grooves between said plurality of reinforcing members, saidauxiliary rod being loosely fitted into a coupling annulus formed atsaid upper ends of said pair of lift rods in such a manner that an upperend of said auxiliary rod engages with said coupling annulus when saidground anchor has been driven into and set in the ground.
 2. A groundanchor as set forth in claim 1, wherein said plurality of reinforcingmembers are semi-elliptical in cross section and are spaced apart fromeach other by a predetermined distance so that said resisting plate maybe bent with a predetermined curvature when said ground anchor has beendriven into the ground.
 3. A ground anchor as set forth in claim 2,wherein the lower ends of the lowermost reinforcing members of saidresisting plate are closed with end members, wherein control or guidemembers are securely joined to rear surfaces of the lower end portionsof said resisting plate in such a manner as to extend downwardly beyondsaid lowermost reinforcing members, and wherein driving-control rods areinserted through said plurality of reinforcing members until they engagewith said end members so that when said ground anchor is driven into theground said resisting plate may be maintained straight but when thedriving impacts are directly applied to said upper end of said resistingplate said driving-control rods are left upwardly behind said resistingplate because of the inertia of said driving-control rods, so that theleg portions of said resisting plate are outwardly moved away from eachother and follow curved paths in opposite directions.
 4. A ground anchoras set forth in claim 3, wherein said resisting plate has an additionalauxiliary rod whose lower end is also firmly fitted to said upper end ofsaid resisting plate and which is loosely fitted into said couplingannulus together with the first-mentioned auxiliary rod, the upper endof said additional auxiliary rod also engaging with said couplingannulus when said ground anchor has been driven and set into the ground.